Machine tool



FIG. 1 is a left perspective view showing our design;

FIG. 2 is a right front perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is right side elevational view thereof;

FIG. 5 is a left side elevational view thereof; and,

FIG. 6 is a rear elevational view thereof. 

The ornamental design for a “machine tool,” as shown and described. 